A massive pile of trash lies near Mall-goers enjoying Sunday’s weather near 14th Street and Jefferson Drive SW. (Craig Hudson/For The Washington Post)

A German au pair in a green sundress stopped across the street from the Washington Monument on her way to the cherry blossoms Sunday and posed for a photograph with the garbage.

“Why don’t they take the trash away?” asked another au pair, Alexandra Ratzinger of Austria.

Plastic-foam lunch containers. A Ritz Crackers box. Rubber gloves. Empty 24-packs of Deer Park water. A Sprite can. A Starbucks cup. Milk crates. Commercial-size boxes of frozen Big-C Premium Select three-eighth-inch straight-cut french fries. All belching forth from, dumped around and cartoonishly piled over a couple of overmatched receptacles as if in some kind of Dr. Seuss book. From one side, the blue and brown cans were no longer visible beneath the crush.

“That’s ridiculous,” said Camaran Pipes, a project manager who stopped along the gravel path from the teeming Smithsonian Metro station to snap a picture of the pile. “This is the nation’s capital!”

Robert Vogel, superintendent of the National Mall and Memorial Parks, said the situation “wasn’t acceptable” and that he called for additional crews about noon.

“But once you get behind, it’s difficult to catch up until the masses leave,” he said.

Officials, he said, “weren’t adequately” prepared for what he described as record crowds for the National Cherry Blossom Festival, though he didn’t have a precise number of visitors. Thousands arrived early, which caused a quick pileup of trash, and trucks had a difficult time getting through the crowds and to the packed sidewalks to pick up waste.

“I think we did drop the ball a little bit,” Vogel said, adding that his staff would review what happened. “Normally this is something we excel at.”

Reactions varied to the torrent of waste that had morphed into a pitiful attraction.

Some visitors were blase, carelessly tossing leftovers onto the growing piles radiating from the cans.

Others, such as Meghan Floyd of Aberdeen, Md., were stymied. She walked up to a precarious, overstuffed can near 14th Street and Jefferson Drive SW that looked like an outsize Jenga game. There was no room inside, and a dumping ground was growing all around. She considered the options for her child’s Uncrustables peanut butter and jelly wrapper and eyed a cup stacked far above the rim as a possible landing site. In the end, she decided to tuck the wrapper into a McDonald’s bag lying on the ground.

“I didn’t know if I could get it in there without knocking everything over,” she said, eyeing the top of the heap. “That’s pretty disgusting.”

Workers struggled to keep up, and there was sympathy for their efforts.

“They’re doing a good job. If you had to clean up all the trash from these people, how fast would you be?” said Carolyn Martese, a retired nurse from Silver Spring.

In some cases, bouts of bad citizenship were the issue. Carelessly tossed greasy napkins and plastic cutlery comingled with pink petals beneath some of the cherry trees that drew the throngs.

Sebastian Bush, 9, spent long stretches Sunday filling and re-filling a plastic grocery bag with the litter he found strewn on the Mall’s grass — including lunch-time remnants from a knoll near a line of food trucks.

“Just stop littering so other people don’t have to clean up after you and then I don’t have to clean it up,” Bush said. When he and his family went to pick up their bikes and ride home to Capitol Hill, one of the locks had been cut and his father’s friend’s bike had been stolen. While they waited for police, Bush kept cleaning up trash near an overstuffed can.

A lot is actually known about trash on the Mall.

About 620 tons of solid waste is collected every year from Mall and Memorials’ trash receptacles, according to a lengthy 2009 study prepared by Keep America Beautiful, a recycling organization. Deliveries to processing facilities fluctuate in frequency and tonnage throughout the year. The “average payload” was about 1.8 tons, but during the Cherry Blossom Festival that number swelled to more than 4.5 tons, according to the report. In January and February, payloads were less than half a ton.

For the past quarter-century, Ronnie Pringle, 62, has cut grass and picked up garbage around the Mall and downtown. On Sunday, the National Park Service worker and his partner used oversize tongs to fill plastic bags with the day’s dripping dregs from around the cans.

Their job is part obstacle-course driver — avoiding jaywalking tourists with their truck is job one — and part park ranger. People kept stopping to ask for directions as they cleaned up the mess. One person tossed a water bottle on the can, and it bounced to the ground as they worked.

“They got to put it somewhere, and we just got to get it up,” Pringle said. “If a lot of them saw what we had to do, they’d give us more credit.”